function  test_coords(flag)


%speed = 3.4852E+02;
%azm_ang = 1.9024E+00;
%lat_ang_sc= -1.3652E+00;
speed      = 400.0
azm_ang    = -180.0
lat_ang_sc = 0.0
% azm_ang > 0 flow to dawn
% azm_ang = 0 from sun
% azm_ang < 0 flow to dusk

lat_ang_mat = -1*lat_ang_sc;

% lat_ang > 0 flow down from ecliptic
% lat_ang < 0 flow up from ecliptic
% lat_ang = 0 along ecliptic

[xx,yy,zz] = sph2cart((3.14159265*(azm_ang)/180.0),(3.14159265*(lat_ang_mat)/180.0),speed)
% xx from sun to earth
% zz up from ecliptic
% yy to dawn

vx = -1*xx;
vy = -1*yy;
vz = zz;

Mtime = datenum(1979,11,4,0,0,0);
[RF,RI] = gse2gsm(Mtime);
vector = [vx,vy,vz];
vecout = mat9vec3(RF,vector);
vxgsm = vecout(1);
vygsm = vecout(2);
vzgsm = vecout(3);
% xgsm from earth to sun
% zgsm up from ecliptic
% ygsm towards dusk.
txt = ['Vxgsm: ', num2str(vxgsm), ' Vygsm: ', num2str(vygsm), ' Vzgsm: ', num2str(vzgsm)];
disp(txt);


%keyboard